Dravya means “substance” or “material” and guna means “quality”. In Ayurvedic medicine, “dravya-guna” is the study of herbal medicine via the specific qualities of each herb.
The word ‘Dravyaguna’ means the science dealing with properties and actions of drugs. This is counterpart of modern pharmacology.
Dravyaguṇa (द्रव्यगुण, “pharmacology”), the Ayurvedic science of medicine in its all aspects, uses rasa (taste) of the substance as the primary tool to assess the pharmacological behavior of any substance.
There are five concepts of the substance, namely:
- rasa (taste),
- guṇa (properties),
- vīrya (potency),
- vipāka (rasa after digestion and metabolism) and,
- prabhāva (specific pharmacological effect),
—which determine and explain the pharmacological behavior of a substance.
These five principles are nothing but manifestations of five mahābhūtas in specific states of activation. Therefore, these principles do indicate the structural and consequent activity of any substance.
Panchabhutas (Akasha, Vayu, Agni, Jala and Prithivi) are regarded as physico-chemical basis of the material objects. When life evolved, out of these five, three came forward to control and regulate the biological functions. These three (Vata, Pitta, Kapha) are known as tridhatu (tridosha in pathological state) having specific functions of Vikshepa (movement) of vata, Adana (assimilation) of pitta and Visarga (growth) of kapha.